ICP Pressure Switch for WPG4304040RKB1 — OEM 1178417 with Tubing | Ships Today

Overview

This OEM pressure switch with tubing is the safety interlock that proves proper draft on the ICP / Tempstar / Heil WPG4304040RKB1 packaged gas furnace. When the inducer motor starts, it creates negative pressure that closes the switch, signaling the control board that venting is clear before the gas valve and igniter are allowed to fire. A stuck, clogged, or out-of-calibration switch — or cracked sensing tubing — prevents ignition and is a common cause of no-heat lockouts. Replacing it restores safe, reliable startup. This listing covers OEM part number 1178417, the factory-correct pressure switch and tubing for this model.

Specifications

Compatibility

Direct-fit replacement for the ICP / Tempstar / Heil WPG4304040RKB1 packaged gas furnace. Match the switch set point (in. w.c.) and port configuration to your original before ordering.

Installation Guide

1. Safety First — Disconnect power at the unit disconnect and verify zero voltage with a multimeter.
2. Access — Remove the furnace control/burner service panel.
3. Document — Photograph the switch wiring and tubing routing before disconnecting.
4. Remove — Pull the spade terminals, disconnect the sensing tube, and unscrew the old switch from its bracket.
5. Install — Mount the new switch, attach the new tubing without kinks, and reconnect the terminals per your photo.
6. Test — Restore power, run a heat cycle, and confirm the inducer proves and the burners light.

Signs You Need a Replacement

• Furnace inducer runs but burners never ignite
• Repeated draft-related lockout codes
• Cracked, brittle, or disconnected sensing tubing
• Switch contacts stuck open or stuck closed when tested

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.